Combinatorial degree bound for toric ideals of hypergraphs

Associated to any hypergraph is a toric ideal encoding the algebraic relations among its edges. We study these ideals and the combinatorics of their minimal generators, and derive general degree bounds for both uniform and non-uniform hypergraphs in terms of balanced hypergraph bicolorings, separators, and splitting sets. In turn, this provides complexity bounds for algebraic statistical models associated to hypergraphs. As two main applications, we recover a well-known complexity result for Markov bases of arbitrary 3-way tables, and we show that the defining ideal of the tangential variety is generated by quadratics and cubics in cumulant coordinates.Comment: Revised, improved, reorganized. We recommend viewing figures in colo

Stvaranje države članice EU-a promicanjem demokracije: slučaj reforme javne uprave u Hrvatskoj

This contribution studies the process of building an EU member state through democracy promotion in the case of Croatia with a special focus on two reform initiatives in the field of Public Administration Reform (PAR). Croatia’s experience is representative of intense efforts of the international community to overcome the consequences of violent state dissolution and civil war. The EU in particular has assisted post-conflict democratization with diplomatic initiatives, the provision of aid, and political conditionality. The Croatian political elite showed great willingness to implement democratic reforms, while at the same time remaining critical of what they viewed as ‘too much’ external interference in domestic state affairs. Based on 30 interviews with Croatian officials, Croatian civil society actors, members of the EU delegation and other representatives of the International donor community, we empirically assess progress and setbacks in Croatia’s public administration reform and explain why some reform initiatives have been successfully implemented while others are still pending.Studija govori o procesu stvaranja članice EU-a promicanjem demokracije u slučaju Hrvatske, s posebnim naglaskom na dvjema reformskim inicijativama iz područja reforme javne uprave (PAR). Iskustvo Hrvatske reprezentativno je za napore međunarodne zajednice da prevlada posljedice nasilnog raspada države i građanskog rata. EU je posebno potpomogao postkonfliktnu demokratizaciju diplomatskim inicijativama, osiguranjem pomoći i političkim uvjetovanjem. Hrvatska politička elita pokazala je veliku spremnost da primijeni demokratske reforme, ali je istovremeno bila kritična prema onome što je smatrano “prevelikim” miješanjem u unutarnja pitanja države. Na temelju 30 intervjua s hrvatskim dužnosnicima, akterima civilnoga društva, članovima EU-delegacije i drugim predstavnicima međunarodne zajednice empirijski se procjenjuju napredak i poteškoće u reformi javne uprave u Hrvatskoj te se objašnjava zašto su neke reforme uspješno implementirane, a druge nisu

Inter-institutional variations in oxytocin augmentation during labour in German university hospitals : a national survey

There are several international guidelines on oxytocin regimens for induction and augmentation of labour, but no agreement on a standardised regimen in Germany. This study collated and reviewed the oxytocin regimens used for labour augmentation in university hospitals, with the long-term aim of contributing to the development of a national clinical guideline

Goodness of fit for log-linear ERGMs

Many popular models from the networks literature can be viewed through a common lens of contingency tables on network dyads, resulting in \emph{log-linear ERGMs}: exponential family models for random graphs whose sufficient statistics are linear on the dyads. We propose a new model in this family, the \emph{$p_1$-SBM}, which combines node and group effects common in network formation mechanisms. In particular, it is a generalization of several well-known ERGMs including the stochastic blockmodel for undirected graphs, the degree-corrected version of it, and the directed $p_1$ model without group structure. We frame the problem of testing model fit for the log-linear ERGM class through an exact conditional test whose $p$-value can be approximated efficiently in networks of both small and moderately large sizes. The sampling methods we build rely on a dynamic adaptation of Markov bases. We use quick estimation algorithms adapted from the contingency table literature and effective sampling methods rooted in graph theory and algebraic statistics. The performance and scalability of the method is demonstrated on two data sets from biology: the connectome of \emph{C. elegans} and the interactome of \emph{Arabidopsis thaliana}. These two networks -- a neuronal network and a protein-protein interaction network -- have been popular examples in the network science literature. Our work provides a model-based approach to studying them

Intrapartum care working patterns of midwives : the long road to models of care in germany

Copyright 2018 ThiemeIntroduction: Midwifery models of care help to enhance perinatal health outcomes, women's satisfaction, and continuity of care. Despite the ubiquitous presence of certified midwives at births in Germany, no research has investigated the diversity of midwives’ practice patterns. Describing the variety of working patterns through which midwives provide intrapartum care may contribute to improving the organisation of midwifery services. Methods: This cross-sectional survey took place in the region of Hannover and Hildesheim, Germany. Midwives attending births and practicing in hospitals and/or out-of-hospital were able to participate. Midwives who did not attend births were excluded. We assessed midwives' scope of services, practice locations, employment patterns, continuity of care, midwife-led births, and midwives' level of agreement with core values of midwifery care. The response rate of the survey was 32.7 % (69/211). Results: We found that midwifery care services can be described according to midwives’ employment patterns. The majority of midwives were employed in a hospital to provide intrapartum care (74.2 %, n = 49), and most also independently offered one or more antenatal and/or postpartum service/s. Only 25.8 % (n = 17) of midwives offered their services independently (laborist model of care). Independent midwives attended births in all three possible settings: hospital, free-standing birth centres and home. Significantly more independent midwives than employed midwives offered antenatal care and lactation consulting. Compared to employed midwives, significantly more independent midwives provided antenatal, intrapartum, and postpartum care to the same women, were more likely to know women before labour, and to offer one-to-one care during labour. Discussion: The most common practice pattern among surveyed midwives was ‘employment in a hospital’ for provision of intrapartum care with additional postpartum and few antenatal services provided on an independent basis. Midwives who worked solely independently reported more continuity and one-to-one intrapartum care with women. Most midwives did not work in patterns that offered continuity of care or consistently provide one-to-one care. Future research should assess whether women in Germany desire more services similar to caseload midwifery

In vitro bioconversion of polyphenols from black tea and red wine/grape juice by human intestinal microbiota displays strong interindividual variability

Dietary polyphenols in tea and wine have been associated with beneficial health effects. After ingestion, most polyphenols are metabolized by the colonic microbiota. The current study aimed at exploring the interindividual variation of gut microbial polyphenol bioconversion from 10 healthy human subjects. In vitro fecal batch fermentations simulating conditions in the distal colon were performed using polyphenols from black tea and a mixture of red wine and grape juice. Microbial bioconversion was monitored by NMR- and GC-MS-based profiling of diverse metabolites and phenolics. The complex polyphenol mixtures were degraded to a limited number of key metabolites. Each subject displayed a specific metabolite profile differing in composition and time courses as well as levels of these metabolites. Moreover, clear differences depending on the polyphenol sources were observed. In conclusion, varying metabolite pathways among individuals result in different metabolome profiles and therefore related health effects are hypothesized to differ between subjects